Objective To establish the control range of monthly nosocomial infection incidences in different departments and put them into practice, to provide a scientific and effective method for nosocomial infection control. Methods The surveillance data about nosocomial infection cases in Nanchong Central Hospital from January 2016 to December 2018 were used to set the warning limits and control limits in different departments based on the theory of medical reference range. From January 2019, the clinical departments would be alerted if their nosocomial infection incidences were beyond the warning limits, and investigated and intervened if the incidences were beyond the control limits. Results The control range of monthly nosocomial infection incidences in different departments had been made. For identifying risk events, the sensitivity was 83.3%, the specificity was 96.2%, the positive predictive value was 29.4%, the negative predictive value was 99.7%, the coincidence rate was 96.0%, and the consistency was medium (kappa=0.419, P<0.001). The effective rate of the initial alert intervention was 83.3%, and the effective rate of the field intervention was 100.0%. Conclusion The establishment and application of the control range of monthly nosocomial infection incidences in different departments can identify potential risk events and realize precise nosocomial infection control.